#include <cstring>
#include <iostream>
#include <algorithm>

#define f(x,l,r) for (int x = l; x <= r; ++ x)

using namespace std;

const int N = 810, M = 3000, INF = 0x3f3f3f3f;

int n, p, m;
int h[N], e[M], ne[M], w[M], idx;
int dist[N], id[N], q[N];
bool st[N];

void add(int a, int b, int c) {
    e[idx] = b, w[idx] = c, ne[idx] = h[a], h[a] = idx ++ ;
}

int spfa(int x) {
    memset(dist, 0x3f, sizeof dist);
    dist[x] = 0;
    
    int hh = 0, tt = 1;
    q[0] = x, st[x] = true;
    
    while (hh != tt) {
        int t = q[hh ++ ];
        if (hh == N) hh = 0;
        st[t] = false;
        
        for (int i = h[t]; ~i; i = ne[i]) {
            int j = e[i];
            if (dist[j] > dist[t] + w[i]) {
                dist[j] = dist[t] + w[i];
                if (!st[j]) {
                    q[tt ++ ] = j;
                    if (tt == N) tt = 0;
                    st[j] = true;
                }
            }
        }
    }
    
    int res = 0;
    f(i, 1, n) {
        int j = id[i];
        if (dist[j] == INF) return INF;
        res += dist[j];
    }
    
    return res;
}

int main() {
    cin >> n >> p >> m;
    
    f(i, 1, n) cin >> id[i];
    
    memset(h, -1, sizeof h);
    while (m -- ) {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        add(a, b, c), add(b, a, c);
    }
    
    int res = INF;
    f(i, 1, p) res = min(res, spfa(i));
    
    cout << res << endl;
    
    return 0;
}